The head of the U.S. bishops conference called for prayers after one person was killed and over a dozen injured during a white nationalist protest in Charlottesville, Virginia.

“The abhorrent acts of hatred on display in Charlottesville are an attack on the unity of our nation and therefore summon us all to fervent prayer and peaceful action,” Cardinal Daniel DiNardo said in a statement Aug. 11.

“We offer our prayers for the family and loved ones of the person who was killed and for all those who have been injured. We join our voices to all those calling for calm.”

After violent clashes between hundreds of white nationalists and counter-protestors in Charlottesville's Emancipation city park, a car plowed into the crowd, killing one and injuring 19, reported the New York Times.

The white nationalist gathering aimed to protest the proposed removal of a statue of Confederate general Robert E. Lee from a local park. The group, which began its demonstration on Friday night, waved Confederate flags and chanted phrases such as “You will not replace us” and “Jew will not replace us.”

By the next morning, hundreds of counter-protestors, from religious leaders to Black Lives Matter activists had gathered and eventually convened with the white nationalists at Emancipation park. While the morning was relatively peaceful, violence began to escalate, with the National Guard arriving to disperse the crowds.

President Donald Trump spoke out against the violence in a statement Saturday, saying he condemned in the strongest possible terms this egregious display of hatred, bigotry, and violence on many sides.”